Ischemic heart disease is a major health problem in the United States. One and half million new cases of heart disease are diagnosed annually; 700,000 of these are diagnosed at the occurrence of an acute myocardial infarction. Nine hundred thousand people die annually of heart disease (http://www.amhrt.org).
The relative risk of mortality from heart disease increases four-fold as the serum cholesterol concentration of the individual goes from 4.32 mmol/L (167 mg/dL) to .gtoreq.6.83 mmol/L (264 mg/dL). (Schaefer, E. J., et al., "Individual Variability in Lipoprotein Cholesterol Response to the National Cholesterol Education Program Step 2 Diet," Am J. Clin. Nutr. 65:823-830 (1997)). At least 25% of the U.S. population has serum cholesterol levels outside the desirable range. (Sempos, C., et al., "The prevalence of High Blood Cholesterol Levels Among Adults in the United States," JAAM, 262:45-52 (1988)). However, a 1% reduction in serum cholesterol concentrations could reduce heart disease by 2%. (Lipid Research Clinics Programs. The Lipid Research Clinics Coronary Primary Prevention Trial Results I: Reduction in Incidence of Coronary Heart Disease, JAMA, 251:351-364 (1984); Lipid Research Clinics Programs. The Lipid Research Clinics Coronary Primary Prevention Trial Results II: The Relationship of Reduction in Incidence of Coronary Heart Disease to Cholesterol Lowering, JAAM, 251:365-374 (1984).
It is known that changing the fat intake in the diet can significantly alter levels of cholesterol, LDLs and HDLs. The National Cholesterol Education Program (NCEP) limits intakes of total fat (&lt;30% of total energy), saturated fat (&lt;10% of total energy), and cholesterol (&lt;300 mg) (Schaefer, E. J., et al., "Individual Variability in Lipoprotein Cholesterol Response to the National Cholesterol Education Program Step 2 Diet," Am J. Clin. Nutr. 65:823-830 (1997)). Patients can expect to experience a reduction in LDL-C (cholesterol in low density lipoproteins, or so-called "bad cholesterol") of 16% to 19%; HDL-C (cholesterol in high density lipoproteins, or so-called "good cholesterol") also declined, 11% for women and 17% for men.
The effects of some different types of soluble fibers on cholesterol levels have been tested. Oat .beta.-glucan can be expected to reduce total serum cholesterol by 2% to 19%. Most studies reported a reduction in LDL-C by 5% to 10%. (Ripsin, C. M. et al., "Oat Products and Lipid Lowering," JAMA 267:3317-3325 (1992)). The HDL-C level did not change in this study. The FDA allows a claim to be made on 3 g of oat .beta.-glucan (as three 0.75 g portions) for its cholesterol-lowering effect. Psyllium containing products are also allowed a claim for 1.7 g of soluble fiber portions on four eating occasions for a total of 7 g per day (Davidson, M. H. et al., Long-term Effects of Consuming Foods Containing Psyllium Seed Husk on Serum Lipids in Subjects with Hypercholesterolemia," Am. J. Clin. Nutr. 67:367-376 (1998)).
However, food products containing high amounts of fiber from such sources as oats and psyllium suffer from the disadvantage that large amounts must be eaten to achieve the cholesterol-lowering effect, adding unwanted extra caloric intake in the diet. These foods frequently suffer from low palatability and undesirable gastrointestinal effects. A more concentrated and palatable nutritional supplement could provide an alternative to ingestion of oats or psyllium, and to drug therapy for hypercholesterolemia.